Thread clamping mechanism for button sewing machines



w. "r. MAXANT 2,685,267 THREAD CLAMPING MECHANISM FOR BUTTON SEWING MACHINES Aug. 3, 1954 4 Sheets-Sheet 1 Original Filed May 3, 1945 A1 1g.3, 1954 T, X N 2,685,267

THREAD CLAMPING MECHANISM FOR BUTTON SEWING MACHINES Original Filed May 5, 1945 4 Sheets$heet 2 g- 3, 1954 w. T. MAXANT 2,685,267

THREAD CLAMPING MECHANISM FOR BUTTON sswmc MACHINES Original Filed May 3, 1945 4 Sheets-Sheet 3 W. T. MAXANT THREAD CLAMPING MECHANISM FOR BUTTON SEWING MACHINES Original Filed May 3, 1945 4 Sheets-Sheet 4 1 ilufiunn. IliTirl I 7 unvlm qk 1 i m 5 K IH.. l||| 2 u W 6 N 4 7 r. y I runh I a g M I ll I. m WU 1 0m IFI III .1:

Patented Aug. 3, 1954 THREAD CLAMPING MECHANISM FOR BUTTON SEWING MACHINES William T. Maxant, Ayer, Mass.

Original application May 3, 1945, Serial No.

591,656. Divided and this application March 5 Claims.

This application is a division of my prior application, filed May 3, 1945, Ser. No. 591,656, now Patent No. 2,563,854, granted August 14, 1951, for Stop Motion Mechanism for Button Sewing Machines.

This invention relates to improvements in button sewing machines, particularly of the character used for sewing flat buttons on work of various kinds, such as strips of cloth, articles of clothing, and the like. It relates more particularly to machines which are used for attaching either twohole or four-hole buttons thereto by stitching through the eyes of the buttons and the cloth, especially such machines as are operated by power.

One object of this invention is to provide for the locking of the thread at the completion of the stitching cycle, and automatically to provide for breaking of the thread and ready separation of the work therefrom.

A still further object of the invention is to improve the construction of the thread lock, the mounting thereof on the face plate instead of the top of the arm; and the actuation of the thread lock or clamp from the power cam of the machine through linkage connections that extend along the under side of the base, up the standard and through the arm to the clamp'mounted on the face plate.

These objects may be accomplished according to one embodiment of the invention by mounting a thread lock or clamp on the head of the machine and through which the thread passes to the needle. A means is provided in the thread lock or clamp for adjusting the action thereof in its released and engaged positions. This thread clamp preferably is actuated by means which functions in timed sequence with the stitching cycle so as to clamp the thread at the completion of the stitching cycle and cause breaking thereof automatically upon movement of the button clamp.

This embodiment is illustrated in the accompanying drawings in which:

Fig. 1 is a side elevation of the button sewing machine showing the thread lock or clamp applied thereto;

Fig. 2 is a partial front elevation thereof;

' Fig. 3 is a horizontal section through the thread clamp on the line 3-3 in Fig. 2;

Fig. 4 is a cross section through the machine and lower portion of the standard;

Fig. 5' is a similar view toward the front of the baseyand J Fi'g; 6'is a partial bottom plan View of the base 1951, Serial N0. 216,976

showing the operating mechanism in elevation and with a part in section, taken on the line 6-4? in Fig. 5.

The machine is adapted for end operation with the operator facing the machine, and with the machine supported on a table, work-bench, or other support, generally designated at S. Accordingly, the machine is constructed with a machine bed designated generally by the numeral i, adapted to be mounted on or secured to the support S.

A hollow base 2 is connected with the bed i, by pivotal connections 3 for swinging movement of the base 2, away from the bed I to gain access to the operating parts of the machine housed within the base. Normally the base is held in a closed position on the machine bed i by a thumb screw t, which extends through an orifice in one side of the base 2 and engages a recess in a lug attached to the bed I, which lug extends upwardly within the base.

The base frame 2 encloses the principal operating parts of the machine and confines these from entanglement of the cloth therewith, as well as presenting a more attractive appearance to the machine. The base 2 has a forward extension 6 on the front end thereof over which the buttons clamp is disposed as hereinafter described, which extension is of appreciably less width than the base, to facilitate the manipulation of the articles and access to the button clamp by the operator.

The base 2 also supports the usual upstanding standard 1 fixed on the base, with an arm 3 extending horizontally from the upper end of the standard 7, which arm carries the usual sewing head 9 at the free end thereof. These parts are hollow and communicate at their lower end with the base 2. These parts comprising the standard arm 8, and sewing head 9 are preferably cast integral and either secured rigidly on the base 2 or cast integral therewith. The outer side of the sewing head 9 is initially open but is enclosed by a cover plate It! which is detachably mounted thereon in the usual manner.

The sewing head 9 has the usual needle bar I I mounted therein and guided at the top through a bushing 12 for reciprocating movement vertically through the head 9. The lower end of the needle bar H carries the usual sewing needle 13. The needle bar H is adapted to be reciprocated sufiiciently far to project the needle 23 into the base extension 6 for cooperating action with sewing instrumentalities contained therein.

For the purpose of reciprocating the needle bar game? I l axially, this needle bar is connected with one end of a rocker arm that extends lengthwise through the hollow arm 8 and has an operative connection with the upper end of a pitman ii. The pitman i'. extends vertically through the standard I as shown in Fig. 4, and downward into the base 2, and is adapted to be reciprocated vertically to cause reciprocating movement of the needle bar H in the head 9.

The lower end of the pitman ll is in the form of an eccentric strap i8 which surrounds an eccentric iS fixed on a main drive shaft 2E that extends lengthwise through the base 2. The drive shaft 26 is journaled in bearings at opposite ends of the base 2 and in a bearing 23 in a transverse partition 23' intermediate the ends of the base. The drive shaft is connected with the operating parts of the machine and drive said parts.

At the other end of the machine the drive shaft 29 carries stitch-forming mechanism, preferably including a rotary looper 26 on a holder 24 on the shaft 213, in cooperating relation with a thread defiector 21, which elements will cooperate with the needle 13 to accomplish the desired stitching action in the manner well-known in the art.

At the opposite end, the drive shaft 26 projects through a bushing externally of the base 2, and has mounted on said projecting end of the shaft fixed and free pulleys 33 and 34, respectively, the former being fixed to the shaft 23 and adapted to receive a drive belt from a suitable source of power. On the extreme end of the shaft is mounted a hand wheel 35 pinned to the shaft for manual turning thereof when desired.

The machine is provided with a shifter yoke, generally designated by the numeral 35, and formed by a pair of shifter arms which embrace opposite sides of the belt and shift the belt from one pulley to the other, either to drive the shaft 20 when the belt engages the pulley 33 or to run free of the shaft on the loose pulley 34. The shifter yoke 36 is connected with a brake shoe 8". which moves v 'th the yoke and carries a lining 33 fixed to the brake shoe 3? to move the lining into frictional engagement with the pulley 33, so as to stop the rotation of the pulley and drive shaft 20 when the brake lining 38 is shifted into engagement therewith. The parts are so disposed that the lining will be shifted into engagement with the pulley 33 when the belt is shifted from this pulley onto the pulley 3 by axial displacement of the yoke 35.

The brake shoe 3? extends transversely of the base 2 and is guided at one end on a pin guided in the base 2. The opposite end of the shoe 3? is formed integral with the support which carries the arms forming the shifter yoke 36. This support is mounted rigidly on a stop shaft All extending in the base 2.

The stop shaft 40 extends lengthwise into the base 2 and is guided in bearing 32 therein for axial movement under the influence of a helical spring 43, which is sleeved over the stop shaft ill, and bears at one end against the partition 23' extending transversely in the base 2 and carrying the bearings 23 and 42. The opposite end of the spring 43 bears against a stop bumper 45 pinned to the stop shaft Ml. The spring 43 normally tends to move the stop shaft to axially rearwardly, unless the shaft is anchored in its operating position as shown. When moved to its released position, the shaft 49 will be moved upward and carry with it the stop bumper 15 and also move the shifter yoke 36 to cause the driving belt to engage the free pulley 34, which will also stop the operation of the machine by the engagement of the brake lining 38 with the pulley 33. For a more detailed explanation of the stop motion mechanism, reference is made to the aforesaid Patent No. 2,563,854, wherein the same is described more fully.

The stop bumper 45 also carries a coiled spring 45 (Fig. 4) mounted in the end thereof, but projecting slightly therefrom in position to engage a stop finger 41 fixed to the drive shaft 20. The

step finger 41 is in such position that its transverse vertical plane of operation will cause it to engage the stop bumper 45 when the latter is moved to its stop position at the completion of a sewing cycle, thus locking the further rotation of the drive shaft 20 until the machine is re-set.

The stop shaft ii] is adapted to be shifted axially to its locked position by means of a hand lever t8 pivotally mounted at 49 in the base 2, so that the upper end of the lever 48 projects above the base in position for convenient reach by the operator for manipulation at the starting of a new sewing cycle. The lower end portion of the lever L18 is bifurcated and engages a pin 50 which projects laterally from the back face of the stop bumper s5. Thus upon shifting the hand lever 38, the stop shaft 40 would be moved to its retracted position, against the tension of the spring 33, and would be locked in said operating position for another sewing cycle.

Provision is made for locking the stop shaft 40 in its retracted or set position. This stop shaft til is accordingly provided with a block 51, fixed thereon and extending downwardly from the stop shaft in position to be engaged by a stop latch 53 that has a shoulder to engage under the block 5i and hold the latter and the stop shaft 40 in retracted positions. The latch 53 has an extended end portion that engages the lower face of the block 5'! when the machine is in its blocked or inoperative position, so that the latch 58 will be ready to engage the block 51 again upon movement of the latter beyond the shoulder.

The latch is normally drawn upward by a coiled spring 6! connected therewith.

The latch 58 is pivotally supported on a bracket or casting 63 which is mounted in the base 2. Said latch 53 underlies a transverse arm 64 integral with the bracket 63 and extending transversely therefrom.

The latch 58 is adapted to be released by a tripper member 85 pivotally mounted at 66 on the transverse arm 64 in a position with one end thereof overlying the latch 58. The opposite end of the tripper member carries a tripper finger 6?, which is slotted and adjustable lengthwise relative to the tripper member 65 by an adjusting screw 68 for providing properly timed operation of the machine.

The finger 61 has a down-turned end 69 in position to be engaged by a stud '49 mounted on the upper face of the upper cam H. The stud E9 is provided with an inclined face to ride under the down-turned end 69 of the tripper finger 61 to cause an upward swinging movement of said finger when engaged by the stud which will force the opposite end of the tripper B5 downwardly and cause the latch 58 to be depressed out of latching engagement with the block 51. This will release the. stop mechanism and move it forward to its blocking position.

The cams are shown at 'H and 12. These cams are mounted on a stub shaft 13 integral-with a worm gear 14 in mesh with a worm 15 fixed to the main drive shaft 20. The stub shaft 13 is journaled on a pin fixed in the base 2 and extending downwardly therein, and is retained in place by means of a screw 16 (Fig. 6) fixed in the end of the journal pin and retaining the stub shaft thereon.

The button clamp is illustrated generally by the numeral 89 and is provided with a pair of clamping jaws 90 between which the button is inserted. The button clamp holds the button in place over the cloth, which latter may be positioned on the cloth plate or underjaw 92.

Provision may be made for actuating the button clamp in properly timed relation and for raising and lowering said clamp, which features are not illustrated or described in detail, but reference may be had to the aforesaid application for a more detailed description thereof.

The usual thread tension devices may be used as indicated generally at I and I46, which tension devices may be of any well-known construction and need not be described in detail.

The thread is supplied from a spool mounted on a stand generally designated at I41 at the back end of the machine, as shown in 'Fig. 1. This stand includes a supporting plate I48 and integrally cast flaring sides I49 formed in one integral piece with said plate, so as to extend over the top and down opposite sides of the pulleys 33 and 34. Thus the thread holder also forms a guard for the pulleys and belt as well as to support the thread.

The thread holder I41 is supported by brackets I56 secured upon the base 2. An upstanding hook member I5I is carried by the stand I41 and has an eyelet in the upper end thereof in position to overlie the spool mounted on the stand for guiding the thread therefrom.

The face plate I6 has th usual eyelets I52 and I53 (Fig. 2) in the upper and lower portions thereof, and an intermediate thread guide generally indicated at I54. A thread guide is shown also at I55 projecting through a slot in the face plate It and carried by the needle bar H.

Mounted on the face plate I6 is a thread clamp, generally designated at I56, through which the thread extends from the eyelet I52 before passing through the thread guide I54 to the needle I3.

The thread clamp I56 is shown more in detail in Fig. 3, and includes a bushing I51 having an end fac portion secured to a stop plate I56 by set screws I59 which pass through the stop plate I56 and through the flanged portions of the bush ing I51 and are threaded into the face plate It! for securing these parts rigidly to the face plate. The bushing I61 has a vertical slot I 6% therethrough for receiving and guiding the thread through the clamp to a position behind the stop plate for clamping action thereagainst.

Slidably mounted in the bushing I 51 is a clamping stud ii having an end face normally spaced from the clamp stop plate I58 but in position to cooperate therewith for clamping the thread therebetween. The thread guide slot I66 is intermediate the opposite sides of the stud IBI, so as to locate the thread in clamping position. The stud is pressed normally backward away from clamping position by a coiled spring I62 sleeved thereover and interposed between the end of the bushing I51 and a collar I63 clamped on the bushing. A pin I64 is telescoped into the end of the clamping stud IEI and guided in the collar I63 for moving the clamping stud to a clamped position, acting as a plunger therefor. A small coiled spring I65 is interposed between the inner end of the plunger I64 and the bottom of the recess in the clamping stud I6I to cushion the action of the plunger thereon. A hand button I66 is attached to the opposite end of the clamping stud I6I for hand release action thereof if required.

Provision is made for actuating the thread clamp I56 automatically in timed relation with the operation of the machine, so that the thread will be clamped immediately upon the completion of the sewing cycle. I have provided; accordingly, a thread clamp push-rod I61 (Fig. 1) slidably mounted in a guide I68 in the head arm 8, and extending lengthwise of said arm. The push-rod I61 extends through the arm 6. The forward end of the push-rod I61 has an upturned abutment portion I69 in position to engage the plunger I64 on the thread clamping stud $61, so as to push the forward end of the stud into clamping relation with the clamp stop plate I66 and hold the thread therebetween.

The back end of the push-rod I61 is pivotally connected with one arm of a bell-crank lever I10 pivotally mounted at I1I at th upper end of the head standard 1. The other arm of the bell-crank lever I10 is pivotally connected with the upper end of a connecting link I12 that extends downwardly through a slot in a guide plate I13 (Fig. 4), mounted at the under side of the base 2.

The lower end of the connecting link I12 carries a laterally projecting pin I14 disposed in position to overlie an end of a thread-lock finger I15. This thread-lock finger I15 is pivotally mounted intermediate its ends on a support I16 carried by the base partition 23'. The opposite end of the finger I15 is beveled at its upper side and in position to be engaged by a stud I11 secured to a side of the stub shaft 13, as shown in Fig. 5.

Thus, upon the completion of a revolution of the gear I l, and with it the cams 1| and 12, the stud I11 will engage the beveled end of the lock finger I15 and depress said beveled end. This action will push upward on the opposite end of the lock finger, and thereby move upward the link I12, swinging the bell-crank lever I10 to impart forward pushing action to the push-rod I61. This will cause a pushing action to be imparted by the offset end I69 against the plunger I64, thereby pressing the stud I6I forwardly against the tension of the spring I65 to clamp the thread between the end of the stud IBI and the clamp stop plate I58 (Fig. 3). This will cause the thread to be clamped at the completion of the stitching operation, and then upon lifting the button clamp the thread will be broken below the clamp.

The location of the thread lock on the face plate, instead of on top of the arm, as in previous machines, provides for a shorter length of thread to stretch when the lifting of the clamp breaks the thread under the button. This results in a quicker break in the thread, which is a decided improvement.

Before starting the sewing operation, the material is placed beneath the button clamp upon the cloth plate 92 of the button clamp. This should be done when the button clamp is in its elevated position, which will aiford ready access thereto for this purpose. The button is then inserted into the clamping jaws 90, and the button clamp 89 is lowered to the position shown in Fig. 1.

The operator then swings the hand lever' 48,

which controls the stop motion mechanism. This action frees the shaft 212 for rotation.

The forward movement of the stop shaft 4i. by the lever 48 slides the belt shifter 35 inwardly which not only shifts the belt from the pulley 34 to the pulley 33, but also releases the brake lining 33 from the face of the pulley 33 which frees this pulley and the shaft connected there- With for rotation by the belt. The drive shaft is then operated by the pulley 33.

The rotation of the drive shaft 22] reciprocates the needle bar H through a stroke suificient to direct the needle downwardly into the base extension 6 for cooperating stitching action with the looper 25 that is rotated by the main shaft 253 on which it is mounted.

As the revolution of the cam shaft 13 is completed, the stud Ill will engage the beveled end of the lever H5, which will lift the opposite end of the lever and push upward on the link H2 I and forwardly on the push rod 167 (Fig. 1) to actuate the clamping stud Hi1 and clamp the thread against movement.

Then upon lifting of the button clamp 89 the thread will be broken therebelow. The work may then be removed or shifted to another position ready for the sewing of another button.

The particular stitching operation need not be described more in detail, but reference may be had to the aforesaid application for this and any other details of the construction and operation of the machine.

While the invention has been illustrated and described in one embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.

I claim:

1. A thread lock for a sewing machine comprising a locking plate, a locking member slidably mounted for coaction with the plate to clamp a thread therebetween, a pin slidably telescoped with the locking member for actuating said member, and a spring interposed between and bearing at opposite ends respectively against said pin and locking member, said spring being urged by movement of the pin to apply yieldable locking pressure to the locking member toward the locking plate.

2. A thread clamp for a sewing machine comprising a clamping plate, a clamping member slidably mounted for movement toward and from the clamping plate adapted to receive a thread therebetween, said clamping member having a shank portion fixed thereto for movement with the clamping member, a pin telescoped in said shank portion, and a coiled spring interposed between the pin and the clamping member and transmitting movement from the pin to said member.

3. A thread clamp for a sewing machine comprising a clamping plate, guide means, a clamping member slidably mounted in the guide means for movement toward and from the clamping plate adapted to receive a thread therebetween, said clamping member having a shank portion fixed thereto for movement with the clamping member, a spring connected with the shank portion acting to move the clamping member in one direction, a pin telescoped in said shank portion, and a coiled spring interposed between the pin and the clamping member and transmitting movement from the pin to said member.

4. A thread clamp for a sewing machine comprising a fixed clamping plate, a bushing connected with the clamping plate, an elongated movable clamping member slidably mounted in the bushing with one end projecting therefrom, the opposite end of the clamping member having a clamping face opposed to the clamping plate adapted to receive a thread therebetween, a coiled spring surrounding the projecting end of the clamping member and acting thereon tending to move said member in one direction, a pin telescoped in said end of the clamping member and slidable relative thereto, and a spring sleeved in said end portion of the clamping member and interposed between said pin and the clamping member.

5. A thread clamp for a sewing machine comprising a fixed clamping plate, a bushing connected with the clamping plate, an elongated movable clamping member slidably mounted in the bushing with one end projecting therefrom, the opposite end of the clamping member having a clamping face opposed to the clamping plate adapted to receive a thread therebetween, a coiled spring surrounding the projecting end of the clamping member and acting thereon tending to move said member in one direction, a pin telescoped in said end of the clamping member and siidable relative thereto, and a spring sleeved in said end portion of the clamping member and interposed between said pin and the clamping member and acting in the opposite direction from the first mentioned spring, and a hand button attached to the opposite end of the clamping member and extending externally of the clamping plate for hand release action of the clamping member on the thread.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 14,433 Watson Mar. 11, 1856 472,094 Willcox et a1 Apr. 5, 1892 1,018,201 Lyons Feb. 20, 1912 1,252,931 Nelson Jan. 8, 1918 1,253,614 Lyons et al Jan. 15, 1918 

